The present invention relates generally to a primary flight display (PFD) for aircraft and, more particularly, to a primary flight display incorporating a three-dimensional tactical display. Despite the great potential for reduction of pilot workload and error that comes with increasingly automated aircraft navigation, the human-machine interface in current flight management systems continues to be an obstacle in reaching this potential that automation technology provides.
The advent of advanced technology aircraft and flight deck automation may reduce the number of functions a flight crew is actively or directly involved in, however, the crew""s responsibility for correct and timely performance of those activities is not reduced. Where advanced automation facilitates a reduction in crew size, the crew""s oversight of cockpit activities may become more difficult as many concurrent activities are performed and monitored by a fewer number of people.
One potential side effect of flight deck automation is flight crew inactivity, fatigue, or complacency. When automation functions reliably, as it does most of the time, it may induce pilots to be less alert in monitoring aircraft behavior and less prepared to take immediate action when needed.
Another problem with flight deck design is that it may lack a human-centered design philosophy that addresses the capabilities and limitations of humans, and the proper role and function of the human in piloting advanced technology aircraft.
Aircraft monitoring may be necessary for long periods of time and the crew may be required to integrate and assimilate information spread over several parts of the interface. In some cases, crew workload may be high at certain times and low at others, possibly resulting in periods of excessive workload followed by periods of boredom. The combination of large amounts of information and poor formatting or integration may serve to increase crew workload.
A weak link in the present system is the human-machine interface, especially that of the flight management system (FMS), which is the system through which most new datalink technologies will work. As currently designed, the FMS has several weaknesses. For example, it is difficult to program, and it is not always apparent to one pilot what inputs another pilot has made. As an integral part of the aircraft operating system in advanced technology aircraft, it cannot be ignored by the pilot, generates large amounts of work at times of high pilot work load (e.g., as with a system failure or late runway change), and data are not always displayed clearly.
Depending on the type of pilot input, the only type of immediate feedback available may be an alphabetical or numerical change on the control display unit.
As an example, the pilot may enter by typing in an altitude for the crossing of a fix near the destination airport. In the extreme case of a very long flight, the delay between the pilot action and the change in aircraft altitude may be more than ten hours. Thus, the pilot must not only have knowledge of the current state of the aircraft, but also of the future programmed states that the aircraft will achieve.
It would therefore be desirable to depict such information regarding the present and future states of the aircraft in a manner that is intuitive and readily recognizable by all members of the flight crew. Particularly useful in achieving this goal would be the use of a graphical or pictorial interface, and even more particularly, a three-dimensional graphical interface. Although flight management system three-dimensional plan maps provide a very compelling display, such are planning tools for strategic purposes, and not for primary flight displays. Thus, it would be desirable to provide improved three-dimensional display for tactical use.
It is, therefore, an object of the present invention to provide an improved three dimensional flight display that is suitable for not only flight planning, but also for tactical use during flight as an integrated component of a primary flight display.
Situational awareness, procedural, and tactical decision-making are the dominant crew errors in accidents. Virtually all approach-to-landing phase accidents involve situational awareness problems. Such findings reinforce those of researchers over the last 40 years. U.S. Navy Capt. George Hoover (Ret.), a pioneer in aviation human factors who has campaigned relentlessly for cockpit displays based on graphical rather than alphanumeric information, is convinced that many situational awareness related accidents could be prevented by improved instrumentation. In Aviation Week and Space Technology (Jun. 17, 1996), he states that xe2x80x9cPeople would rather have data presented to them in pictures instead of, symbols. Humans interpret graphical information faster, process it more efficiently and make fewer mistakes when applying it.xe2x80x9d
Situational awareness, which depends upon how well the pilot is provided with information relative to the current surroundings, such as other aircraft or threats in the immediate area, will become more important in the near future when the Air Traffic Control (ATC) system changes to the Air Traffic Management system. Pilots will have more responsibility for their flight trajectory since they will often be in control rather than the ATC. A good awareness of this trajectory into the future is important. xe2x80x9cFree flightxe2x80x9d envisions an aircraft flying any trajectory with intermittent ATC control when conflicts occur. In Europe, the scheme envisioned is for an air crew to request a flight path, which is then approved by ground controllers, and then fly that trajectory under continuous positive ATC control.
In either case, the pilot will be much more responsible for and creative in determining his or her flight path and trajectory for a given flight. It would, therefore, be desirable to provide a three-dimensional map that provides immediate and future situational awareness.
It is, therefore, another object of the present invention to provide a primary flight display with data presented in a three-dimensional format that provides a flight crew with highly increased situational awareness, thus enhancing a flight crew""s ability to compensate and correct for flight path errors.
The display according to the present invention is integral to providing an interface that is easy to program and wherein inputs to the system are apparent to other members of the flight crew are pictorially displayed, both in terms of the data entered by the aircrew and the flight management system actions to be taken as a result of the data entry, both immediate and in the future. The display format in accordance with the present invention is useful under the current system of airways or xe2x80x9chighways in the skyxe2x80x9d by allowing pilots to determine whether flight automation is correctly programmed to maintain proper heading, altitude, according to the flight plan, or instrument landing system (ILS) parameters such as localizer and glide slope. The display according to the present invention will also meet the needs of the future by providing a human-machine interface that presents data conveniently, simply, and intuitively in a format that is easily assimilated and interpreted by a human operator, and that will be especially useful in allowing pilots to readily and intuitively evaluate if they have correctly programmed the automation for their intentions as more pilots assume more control over their flight trajectories.
The objects of the present invention are provided by a primary flight display with tactical three-dimensional display. The primary flight display according to the present invention combines a three-dimensional map with other navigation data including, inter alia, airspeed, attitude information, altitude, and heading information. The information is combined in an area that is concise, yet easy to read. The display format according to the present invention is most advantageously sized to be displayed on displays larger than 6 inch by eight inch display monitors, for example 8xc3x9710 inch or larger displays. However, it is also within the contemplation of the present invention that the display format be sized to be retrofitted on conventionally sized display monitors commonly found in flight decks, for example, six inch by eight inch display monitors.
In a preferred embodiment according to the present invention, the display format comprises an upper portion comprising an electronic depiction of conventional flight instrumentation and a lower portion comprising a three-dimensional map.
In an especially preferred embodiment according to the present invention, the display also incorporates vertical and lateral deviation and a top terrain view.
In addition, the display format according to the present invention can be used in conjunction with a Traffic Alert and Collision Avoidance System (TCAS) and systems designed to prevent Controlled Flight into Terrain (CFIT) such as the Ground Proximity Warning System (GPWS) and Ground Collision Avoidance System (GCAS).